Production,nutrient cycling and soil compaction to grazing of grass companion cropping with corn and soybean

Agricultural management systems are needed to simultaneously enhance production, promote plant diversity, improve nutrient cycling and reduce soil compaction. We investigated the effects of intercropped forage grass on production of corn (Zea mays L.) harvested for silage at 0.20 and 0.45 m height in the summer, as well as on production of subsequent forage, soybean [Glycine max (L.) Merr.] harvested for silage, nutrient cycling and soil responses on a Typic Haplorthox in Botucatu, São Paulo State, Brazil. Palisade grass cv. BRS Piatã [Urochloa brizantha cv. BRS Piatã] was the introduced companion crop with corn (Years 1 and 2), while signal grass [Urochloa decumbens cv. Basilisk] was the residual weedy species in comparison. Guineagrass cv. Aruãna [Megathyrsus maximus cv. Aruãna] was the introduced companion crop with soybean (Year 3), with only a residual effect of crop systems from the previous two years. After the corn silage harvest, pasture was grazed by lambs in winter/spring using a semi-feedlot system. When cut at 0.45 m compared with 0.20 m height, corn intercropped with palisade grass had greater leaf nutrient concentration, improved agronomic characteristics, forage mass of pasture for grazing by lambs, greater surface mulch produced, and greater quantity of N, P and K returned to soil. Greater soil organic matter, P, K and Mg concentration, and base saturation in the surface soil depth and lower soil penetration resistance at all depths occurred at 0.45 m than at 0.20 m corn silage cutting height intercropped with palisade grass. Analyzing the system as a whole, harvesting corn silage crop with palisade grass intercrop at 0.45 m height was the most viable option in this integrated crop-livestock system.     

“Non-Conformist Crystallography”

Now, 25 years or so after the quasi-crystal affair, we can perhaps see the development of crystallography, as it turns into nanotechnology and molecular biology, in a still longer-term perspective as part of the struggle to understand the universe rationally in the face of competing theories and superstitions. We follow changes of paradigm in investigations of the structure of matter and in various dualities, in particular in the dialogue between materials and information. In a small way, the discovery of quasi-crystals exhibits the interactions between the different world representations, Platonic, mental and physical (here labelled P, Q, R) and between conceptions of Laws, Natural, Mathematical, Civil/Military and Divine.     

3D Image Segmentation of Aggregates from Laser Profiling

Abstract: In digital imaging of discrete particles, such as stone aggregates, segmentation is one of the most important processes. Automated scanners of different designs use cameras or lasers to obtain digital images of groups of aggregate particles. To accurately determine particle size and shape parameters, each particle region in the image must be isolated and processed individually. Here, a method for segmenting a particle image acquired from laser profiling is developed using a Canny edge detector and a watershed transformation. Canny edges with rigorous and liberal threshold values are used to outline particle boundaries on a binary image and to check the validity of watersheds, respectively. To find appropriate regional minima in the watershed transformation, a varying search window method is used, where the number of neighboring pixels being compared with the pixel of interest is determined from the height value of the pixel. Test results with this method are promising. When implemented in automated systems that are designed to rapidly assess size and shape characteristics of stone particles, this technique can not only reduce the amount of time required for aggregate preparation, but also increase the accuracy of analysis results.     

Reviews

Caspar David Friedrich and the Subject of Landscape

by Joseph Leo Koerner, Reaktion Books, 1990

History and precedent in environmental design

by Amos Rapoport, New York: Plenum Press, 1990

Natural Landscapes of Britain from the air

edited by Nicolas Stephens, Cambridge University Press, 1990,

pp. 288, 140 b/w photographs, £19.50

Images of Prehistory

by Peter Fowler and Mick Sharp, Cambridge University Press, 1990,

ISBN 0-521-35646-6, £19.50

Landscape. Monuments and Society: the prehistory of Cranborne Chase

by John Barrett, Richard Bradley & Martin Green, Cambridge University Press, 1991 ISBN O-521-32128X. £35.00 hb.

The Spectacle of Nature

by Nicholas Green, Manchester University Press, 1990

Introduction to Landscape Design

by John L. Motloch, New York: Van Nostrand Reinhold, 1991, 307pp.

Taming the Great South Land: a history of the conquest of nature in Australia,

by William J. lines, Sydney: Allen & Unwin, 1991, pp. xx + 337, 38 plates. Available from UCL Press Ltd., London, £30.00 hb.

River Projects and Conservation: a manual for holistic appraisal.

edited by John L Gardiner, Chichester: John Wiley, 1991, ISBN 0-471-92643-4, 236 pp £50.00 hb

Imagined Country

by John Rennie Short, London and New York: Routledge, 1991

Living in a New Country: history, travelling and language,

by Paul Carter, London: Faber & Faber, 1992. x + 214 pp.

ISBN 0-571-16329-7, $22.95 Hb.

The Aesthetics of Environment

by Arnold Berleant, Philadelphia: Temple University Press, 1992,

ISBN 0-87722-993-7, 240 pp., $34.95.

The English Rural Community

edited by Brian Short. Cambridge:Carnbridge University Press, 1992,

Hb 0-521-40537-8 £35.00 : Pb 0-521-40567-X, £12.95, 239pp.

Fields of Vision: landscape imagery and national identity in England and the United States

by Stephen Daniels, Oxford: Polity Press, 1993, pp.xii + 255,

ISBN 0-7456-0450-1, £39.50,

The Palladian Landscape

by Denis Cosgrove, London: Leicester University Press, 1993, pp. xv + 270.

Nature Pictorialised: “the view' in landscape history

by Gina Crandell, Baltimore: John Hopkins Univ. Press, 1993, pp.196,

ISBN 0-8018-4397-9

edited by David Seamon, Albany: State University of New York Press, 1993, pp. xviii + 363, ISBN 0-7914-1277-6, $19.95 pb, $59.50 hb

Restoring Period Gardens: from the Middle Ages to Georgian times.

by John Harvey, Princes Risborough: Shire, Second edition, 1993,

pp.112, ISBN 0-7478-0200-9, £4.99 pb.

Empty Meeting Grounds: the tourist papers

by Dean McCannell, London: Routledge, 1992,

Dwelling, Seeing, and Designing: toward a phenomenological ecology

346pp, ISBN 0-415-05693-4.

Towards a new landscape

Bernard Jacobson Gallery, 14A Clifford Street, London, W1X 1RF, 1993,

pp.128, ISBN 1-872784-12-7

Place in Space: Human Culture in Landscape

edited by Hana Svobodova & Jan Uhde, Wageningen: Pudoc Scientific, 1993, pp. 128, ISBN 90-220-1089-9, $56.00.     

Book reviews

Edge of Empire: Postcolonialism and the City. Jane M. Jacobs. London and New York, Routledge, 1996, 193 pp., £12.99 pb, ISBN 0–415–12007–1

Land for Industrial Development. David Adams, Lynne Russell & Clare Taylor‐Russell. London, E.&F.N. Spon, 1994, 289 pp., £37.50 hb, ISBN 0–419–19180–1

Urban Policy in Practice. Tim Blackman. London, Routledge, 1994, 320 pp., £14.99 pb, ISBN 0–415–09300–7

Planning, the Market and Private House‐building. G. Bramley, W. Bartlett & C. Lambert London, UCL Press, 1995, 192 pp., £11.95 pb, ISBN 1–85728–163–2

Retail Planning Policies in Western Europe. Ross Davies. London, Routledge, 1995, 304 pp., £45.00 hb, ISBN 0–415–10997–3

Transport Concepts in European Cities. Tim Pharoah & Dieter Apel. Aldershot, Avebury, 1995, 291 pp., £42.50 hb, ISBN 1–859–72094–3

Building a New Heritage: Tourism, Culture and Identity in the New Europe. G.J. Ashworth & P.J. Larkham (Eds). London, Routledge, 1994, 278 pp., hb (out of print), ISBN 0–415–07931–4

Fractal Cities: A Geometry of Form and Function. Michael Batty & Paul Longley. London, Academic Press, 1994, 394 pp., £38.00 hb, ISBN 0–124–55570–5     

New directions in migration research

This paper takes several surveys of the literature concerning migration research as its starting point and directs the reader toward a number of potentially fruitful lines for future research. Major sections include one on modeling migrant choice in which the pros and cons of using gross versus net migration measures are discussed. A second introduces and discusses the concept of a spatial choice set, which has the potential to be implemented with laboratory experimental techniques. The third involves a wide-ranging discussion of new directions in modeling the interrelationships between employment and migration.This paper was prepared in connection with the Western Regional Science Association's President's Panel, Molokai, Hawaii, February 1990.